Broadcast data from a source host (host 0 by default) to all other hosts.
Parameters:
in_tree (Any) – pytree of arrays - each array must have the same shape across the
hosts.
is_source (bool | None) – optional bool denoting whether the caller is the source. Only
‘source host’ will contribute the data for the broadcast. If None, then
host 0 is used.
Returns:
A pytree matching in_tree where the leaves now all contain the data from the
first host.